9.29<!DOCTYPE html>
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<script>
    let sum = 0;
    for(let i=1;i<101;i++){
        sum+=i;
    }
    console.log(sum);
    console.log('-----------');
    let i=0;
    while(i<101){
        if(i%2==0){
            console.log(i);
        }
        i++;
    }
    console.log('-----------');
    let a =10;
    while(a<10){
        console.log('执行while循环');
    }
    let b=10;
    do{
        console.log('执行do---while的循环');
    }while(b<10)
    let str;
    for(letri=0;i<4;i++){
        str='';
        for(let j=0;j<5;j++){
            str += '*';
        }
        console.log(str+'\n');
    }
</script>
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